Abstract:Thirty-six healthy Type A men (means = 44.4 years) were randomly assigned to either an aerobic exercise training group or a strength and flexibility training group. Subjects completed a comprehensive psychological assessment battery before and after the exercise programs consisting of behavioral, psychometric, and psychophysiological testing. The behavioral assessment consisted of repeated Type A interviews that were videotaped for subsequent component analyses. The psychometric testing included two self-report questionnaires to assess Type A behavior. The psychophysiological test consisted of a standard behavioral challenge, a mental arithmetic task, performed while cardiovascular responses were monitored. Aerobic exercise (AE) training consisted of 12 weeks of continuous walking or jogging at an intensity of at least 70% of subjects' initial maximal oxygen consumption (VO2max) as determined by an initial treadmill test. Strength and flexibility (SF) training consisted of 12 weeks of circuit Nautilus training with no aerobic exercise. After 12 weeks of exercise, the AE group increased their VO2max by 15%, while the SF group did not change. Both groups experienced decreases in overt behavioral manifestations of the Type A behavior pattern and self-reported Type A traits. However, the AE group showed an attenuation of heart rate, systolic and diastolic blood pressure, and estimated myocardial oxygen consumption (MVO2) during the task and had lower blood pressure, heart rate, and (MVO2) during recovery. In contrast, the SF group showed a significant reduction only in DBP during the task, which was likely due to habituation. These results support the use of aerobic exercise as a method for reducing cardiovascular risk among healthy Type A men.